Also known as: Heart tumor
Nick, Arizona's best friend, has a cardiac tumor invading his right ventricle and tricuspid valve. The surgical team discovers during the operation that the tumor has infiltrated too deeply to resect safely, forcing them to close without completing the procedure. This diagnosis drives a major emotional arc with Arizona confronting her avoidance of Nick's illness.
Also known as: Parasitic worm infection
Jake presents with stomach perforation, intestinal obstruction, and enlarged liver after returning from his Thailand honeymoon. The team discovers a gnathostoma worm that has migrated through his tissues and nested in his cervical spine (C3-C5), causing progressive paralysis. Derek performs urgent spinal surgery to prevent quadriplegia. This case creates significant conflict between Bailey and Ben on their day off.
Also known as: Worm under the skin
Jake's wife Marion has a visible worm under the skin of her arm from the same parasitic infection acquired in Thailand. Meredith discovers it during examination and it requires surgical extraction.